Classified FBI files that have now been made public reveal that the American domestic intelligence agency spied on the Beatles and Michael Jackson in case they disturbed national security. The secret files say that other stars like Frank Sinatra, John Denver, Jimi Hendrix and the boss of Kentucky Fried Chicken (KFC) were also spied upon, The Sun reported.The FBI described John Lennon as a “radically orientated” druggie. The agency mentions him and wife Yoko Ono in around 200 pages for posing nude for an album.King of Pop Michael Jackson was mentioned in the FBI files after the agency helped California police investigate child molestation charges against him. A total of 34 pages are devoted to late guitar legend Jimi Hendrix on his marijuana possession. The files also mention that he was a contributor to a hippy magazine called “The Chicago Kaleidoscope”.US agents also took interest in the band Kiss and rap star Tupac. A dossier was opened on Frank Sinatra over links with the mafia, and country singer John Denver was also suspected to have connections with the mob. Jimi Hendrix and the Grateful Dead were the subject of drug investigations, while Elvis Presley was noted as a victim of extortion bids.KFC owner Colonel Sanders was also probed, after he asked FBI boss John Edgar Hoover for his autograph.